In the Maaspoort district is a centuries-old duck decoy, a Dutch invention specially designed to trap wild ducks. It's located in the Burgemeester van Zwietenpark and was created between 1665 and 1739 when the tasty birds were caught to grace the tables of wealthy Dutchmen. The fresh water lake attracts the ducks and they enter the wooden trap box via the curved ditches. Once in the main box, the animals were locked up and could not escape. These days the remaining duck decoys are used for precisely the opposite reason – as a duck refuge! The ducks are able to live undisturbed in a quiet environment away from humans.